1. Field of the Invention
The present invention relates, in general, to transformers, and in particular, to an improved padmount transformer enclosure.
2. Information Disclosure Statement
A preliminary patentability search in Class 174, subclass 50, and Class 312, subclasses 223.1 and 100, produced the following patents, which appear to be relevant to the present invention: Nelson et al., U.S. Pat. No. 3,014,158, issued Dec. 19, 1961; Fisher, U.S. Pat. No. 3,376,086, issued Apr. 2, 1968; Main, U.S. Pat. No. 4,003,610, issued Jan. 18, 1977; Nilsson, U.S. Pat. No. 4,466,676, issued Aug. 21, 1984; Borgmeyer et al., U.S. Pat. No. 5,189,257, issued Feb. 23, 1993; Dirk, U.S. Pat. No. 5,573,319, issued Nov. 12, 1996; Marusinec, U.S. Pat. No. 5,783,775; Arizpe et al., U.S. Pat. No. 5,823,646; Marusinec et al., U.S. Pat. No. 5,889,231, issued Mar. 30, 1999; and Reinke et al., U.S. Pat. No. 6,066,802, issued May 23, 2000.
Padmount transformer enclosures are used in electrical power distribution systems to contain distribution transformers used to step down voltage from the high voltage terminal of an underground electrical distribution systems to the low voltage terminal thereof going to the end user""s electrical system, etc. A typical prior art padmount transformer enclosure includes a tank for holding the core/coil assembly of the transformer immersed in oil or the like, and a wiring cabinet having high and low voltage wiring compartments for enclosing the high and low voltage bushings, respectively, of the transformer, etc. In order to prevent unauthorized access to the core/coil assembly of the transformer held within the tank of the padmount transformer enclosure, the most common prior art practice is to weld a cover over the top of the tank. Other prior art tank covers are secured with carriage bolt-nut assemblies, and include some means for shield the nuts, etc. Such shielding means result in a cover that protrudes past the top of the tank cover by several inches and causes water, etc., to be trapped along the edge of the cover. The wiring cabinet of a typical prior art padmount transformer enclosure includes left and right sidewalls, and left and right lockable doors that swing open, exposing the high and low voltage wiring compartment. One of the doors swings out to the right and the other door swings out to the left, leaving the front completely open, but the right and left sidewalls remain fixed in place.
Nothing in the known prior art discloses or suggests the present invention. More specifically, nothing in the known prior art discloses or suggests a padmount transformer enclosure that allows the doors and the side walls of the wiring compartment to be opened so that the wiring compartment is totally exposed on all three sides; or a padmount transformer enclosure including a liquid tight tank having a cover that can be removed with simple hand tools without requiring removal or disassembly of the wiring compartment, and having a tamperguard which prevents removal of the cover except by authorized personnel.
The present invention provides an improved padmount transformer enclosure for a 3-phase padmount distribution transformer or the like. One basic concept of the present invention is to provide the terminal or wiring compartment of a padmount transformer enclosure with left and right side panels that are hinged to the transformer tank front panel so that the side panels of the wiring compartment can swing open to allow the wiring compartment to be totally exposed or open on all three sides. Another basic concept of the present invention is to provide the transformer tank of a padmount transformer enclosure with a tamper proof cover that can be removed with simple hand tools by authorized personnel.
One object of the present invention to provide a padmounted, distribution transformer enclosure with a tank cover that can be removed by the manufacturer or end user with simple hand tools, more easily than prior art tank covers.
Another object of the present invention is to provide such a transformer enclosure with a tamperguard which requires access to the interior of a lockable wiring compartment for removal of the tank cover, with the tamperguard positioned in a box section or channel in the tank beneath the cover which strengthens the tank and allows for a unique, recessed tamperguard located under the cover rather than covering the top edge of the cover, so that there is no tendency to trap water along the edge of the cover.
Another object of the present invention is to provide a padmounted, distribution transformer enclosure with a wiring compartment that can be swung open to be totally exposed on all three sides, allowing work to be done within the wiring compartment without any obstructions caused by the cabinet.